faster booting

Roland Smith rsmith at xs4all.nl
Wed Mar 5 21:03:06 UTC 2008


On Wed, Mar 05, 2008 at 03:06:39PM -0500, Daniel Feenberg wrote:
<snip>
> So, is there advice anywhere about speeding up the boot process? It appears 
> that most of the 1 minute 45 seconds to boot our system is wait time for 
> checking the existence of non-existant hardware and would not be 
> appreciable reduced with a faster CPU or disk. Are there kernel options 
> that we could use to avoid this checking? Would recompiling the kernel in 
> some specialized way help?

You should build a custom kernel with only the devices and options that
you need in it. Starting from the GENERIC kernel config and with dmesg
output in hand you should be able to remove a lot of unneeded
drivers. For instance, probing a floppy drive takes relatively
long. Remove all network devices except the ones you actually use. Same
goes for the SCSI card drivers and RAID controllers. Do not mess with
the "options" lines unless you know what you're doing. And if you remove
"device" lines, look at its manual page to check that it is not a
prequisite for another driver that you do need. Do not remove the
devices random, loop, ether pty and md.

I always use 'makeoptions MODULES_OVERRIDE=""' in my kernel config so
that no kernel modules are built or installed.

Another way to shorten boot time is to disable all unneeded services.

Roland
-- 
R.F.Smith                                   http://www.xs4all.nl/~rsmith/
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